How Much Sleep Do Adults Need? 7 to 9 Hours a Night

Experts recommend that adults sleep between 7 and 9 hours a night, according to NHLBI: How Much Sleep Is Enough?. The same page says adults who sleep less than 7 hours a night may have more health issues than those who sleep 7 or more hours a night.

Sleeping more than 9 hours a night is not necessarily harmful, that page says, and may be helpful for young adults, people who are recovering from sleep deprivation, and people who are sick. NINDS: Brain Basics: Understanding Sleep says most adults require 7-9 hours of sleep at night. It also says there is no magic amount of sleep that works for everybody of the same age.

How do the recommended hours differ by age group?

Sleep needs change with age, the Brain Basics page says. The table below lists the hours printed for each age group on four of the pages cited in this guide. The How Much Sleep Is Enough? page says its figures are recommended hours of sleep, including naps.

Read down the table from teens to adults: the bottom of the range goes from 8 hours to 7 hours, a difference of 1 hour, and the top goes from 10 hours to 9 hours, also 1 hour. The adult range of 7 to 9 hours is 2 hours wide (9 minus 7).

Older adults need about the same amount of sleep as all adults, seven to nine hours each night, the Sleep and Older Adults page says. It adds that older people tend to go to sleep earlier and get up earlier than they did when they were younger. MedlinePlus says some people think adults need less sleep as they age, but there is no evidence to support this.

Two publications kept on this site print 7–8 hours for adults. The booklet Your Guide to Healthy Sleep, originally printed November 2005 and revised August 2011, says research suggests that adults need at least 7–8 hours of sleep each night to be well rested. The easy-to-read fact sheet titled "In Brief: Your Guide To Healthy Sleep," revised September 2011, says most adults need 7–8 hours of sleep each night.

What counts as not getting enough sleep?

Sleep deprivation is a condition that occurs if you don't get enough sleep, according to NHLBI: What Are Sleep Deprivation and Deficiency?. That page calls sleep deficiency a broader concept. It occurs if you have one or more of the following:

• You don't get enough sleep (sleep deprivation).
• You sleep at the wrong time of day.
• You don't sleep well or get all the different types of sleep your body needs.
• You have a sleep disorder that prevents you from getting enough sleep or causes poor-quality sleep.

MedlinePlus says it's not just the number of hours of sleep you get that matters, and that the quality of the sleep you get is also important. People whose sleep is frequently interrupted might not get enough of certain stages of sleep, it says.

After several nights of losing sleep, even a loss of just 1 to 2 hours per night, your ability to function suffers as if you haven't slept at all for a day or two, according to NHLBI: How Sleep Affects Your Health. The Brain Basics page says many people feel they can "catch up" on missed sleep during the weekend. Depending on how sleep-deprived they are, it says, sleeping longer on the weekends may not be enough to replace the sleep they've missed.

The sleep deprivation and deficiency page gives two counts. According to the Centers for Disease Control and Prevention, it says, about 1 in 3 adults in the United States reported not getting enough rest or sleep every day. Nearly 40% of adults report falling asleep during the day without meaning to at least once a month.

That page also says sleep deficiency is linked to many chronic health problems, including heart disease, kidney disease, high blood pressure, diabetes, stroke, obesity, and depression. It calls it a common myth that people can learn to get by on little sleep with no negative effects.

What are the signs of problem sleepiness?

How sleepy you feel during the day can help you figure out whether you're having symptoms of problem sleepiness, the How Sleep Affects Your Health page says. You might be sleep deficient, it says, if you often feel like you could doze off while:

1. Sitting and reading or watching TV
2. Sitting still in a public place, such as a movie theater, meeting, or classroom
3. Riding in a car for an hour without stopping
4. Sitting and talking to someone
5. Sitting quietly after lunch
6. Sitting in traffic for a few minutes

MedlinePlus lists three questions to ask yourself. Do I have trouble getting up in the morning? Do I have trouble focusing during the day? Do I doze off during the day? If you answered yes to any of these questions, you may need to improve your sleep habits, it says.

A patient booklet on this site, Facts About Problem Sleepiness, is dated September 1997. It says that when sleepiness interferes with daily routines and activities, or reduces the ability to function, it is called "problem sleepiness." Its list of signs includes falling asleep while driving, struggling to stay awake when inactive, such as when watching television or reading, and having to take naps on most days. If you are consistently getting less than 8 hours of sleep per night, it says, more sleep may be needed.

The How Sleep Affects Your Health page says driver sleepiness is estimated to be a factor in about 100,000 car accidents each year, resulting in about 1,500 deaths. The In Brief fact sheet on this site says that if you feel sleepy while driving, pull off the road to a safe place and take a nap for 15–20 minutes.

Which sleep habits do the sources say help?

First, make sure that you give yourself enough time to sleep, says NHLBI: Healthy Sleep Habits. The checklist below collects steps from that page and from the MedlinePlus, Brain Basics and Sleep and Older Adults pages cited above, and names which page says what.

1. Keep one schedule. The Healthy Sleep Habits page says to go to bed and wake up at the same time every day. Between weeknights and weekends, it says to limit the difference to no more than about an hour.
2. Quiet the last hour. The same page says to use the hour before bed for quiet time and to avoid intense exercise and bright artificial light, such as from a TV or computer screen.
3. Watch caffeine and nicotine. The Healthy Sleep Habits page says the effects of caffeine can last up to 8 hours, so a cup of coffee in the late afternoon can make it hard to fall asleep at night. It calls nicotine and caffeine stimulants.
4. Time meals and drinks. The Healthy Sleep Habits page says to avoid heavy or large meals within a few hours of bedtime and to avoid alcoholic drinks before bed. The Sleep and Older Adults page says to avoid eating large meals within two to three hours of your bedtime.
5. Exercise earlier. The Brain Basics page says to exercise for at least 30 minutes most days of the week, but not within a few hours of bedtime. The Sleep and Older Adults page says not within three hours of your bedtime.
6. Set up the bedroom. The Healthy Sleep Habits page says to keep your bedroom quiet, cool, and dark.
7. Limit naps. The Healthy Sleep Habits page says adults should nap for no more than 20 minutes. MedlinePlus says not to take a nap after 3 p.m.
8. Get up if you are awake. MedlinePlus says that if you can't fall asleep for 20 minutes, get up and do something relaxing.

For shift workers, the Healthy Sleep Habits page lists taking naps, keeping the lights bright at work, and limiting caffeine use to the first part of the shift. If you're still not able to fall asleep during the day or have problems adapting to a shift-work schedule, it says to talk with your doctor about other options to help you sleep.

When do the sources say to talk to a provider?

The How Much Sleep Is Enough? page says to talk to your doctor if you think you are sleeping too much or too little. MedlinePlus says to see a health care provider if you have continued trouble sleeping, and that you may have a sleep disorder, such as insomnia or sleep apnea. The Brain Basics page says to see a doctor if you have problems sleeping or if you feel unusually tired during the day.

The Sleep and Older Adults page says that if you're always sleepy or you find it hard to get enough sleep at night, it may be time to talk with a doctor. It suggests keeping a sleep diary for a couple weeks if you have trouble sleeping: track when you go to bed, when you wake up during the night, and when you wake up for the day. The diary will help you identify patterns to discuss with your doctor, it says.

The In Brief fact sheet on this site says to talk to your doctor if you have any of the signs of a sleep disorder it lists. Four of them are:

• You consistently take more than 30 minutes each night to fall asleep.
• You consistently awaken several times each night and then have trouble falling back to sleep, or you awaken too early in the morning.
• You often feel sleepy during the day, you take frequent naps, or you fall asleep at inappropriate times during the day.
• Your bed partner says that when you sleep, you snore loudly, snort, gasp, make choking sounds, or stop breathing for short periods.

Facts About Problem Sleepiness says that if you think you are getting enough sleep, but still feel sleepy during the day, check with your doctor to be sure your sleepiness is not due to a sleep disorder. The Brain Basics page says most sleep disorders can be treated effectively.

Also on this site is a report on insomnia dated September 1998, with its audience listed as health professionals. It says about one-third of patients seen in a primary care setting experience occasional insomnia, and 10 percent may suffer from chronic sleep problems.

This guide is general education, and how much sleep is right for you is a question for your own health care provider. More pages are listed on the sleep topic page.